It was 2am on August 16 2002 and Don Shugak was making his rounds as a field production operator for British Petroleum in Alaska. He had the radio tuned to public station KBRW and watched for caribou as he drove his pick-up truck across the desolate Arctic tundra of the Prudhoe Bay oilfield. Part of his job was to monitor the restarting of wells shut for maintenance; every so often he would jump out to “check the vitals” on wells spread 25ft to 50ft apart.

After 12 years with BP, the Alaska native knew the routine, checking up to 100 wells, on clusters miles apart, during a 12-hour shift on America’s biggest oilfield. But he was never complacent: “There is always that risk factor when you are dealing with pressure and hydrocarbons.”